Merge pull request #1 from davidoram/feature/puttext

Added support for putText

opencv/cxcore.go

@@ -566,6 +566,48 @@ func Circle(image *IplImage, pt1 Point, radius int, color Scalar, thickness, lin
 	)
 }
 
+const (
+	CV_FONT_HERSHEY_SIMPLEX        = int(C.CV_FONT_HERSHEY_SIMPLEX)
+	CV_FONT_HERSHEY_PLAIN          = int(C.CV_FONT_HERSHEY_PLAIN)
+	CV_FONT_HERSHEY_DUPLEX         = int(C.CV_FONT_HERSHEY_DUPLEX)
+	CV_FONT_HERSHEY_COMPLEX        = int(C.CV_FONT_HERSHEY_COMPLEX)
+	CV_FONT_HERSHEY_TRIPLEX        = int(C.CV_FONT_HERSHEY_TRIPLEX)
+	CV_FONT_HERSHEY_COMPLEX_SMALL  = int(C.CV_FONT_HERSHEY_COMPLEX_SMALL)
+	CV_FONT_HERSHEY_SCRIPT_SIMPLEX = int(C.CV_FONT_HERSHEY_SCRIPT_SIMPLEX)
+	CV_FONT_HERSHEY_SCRIPT_COMPLEX = int(C.CV_FONT_HERSHEY_SCRIPT_COMPLEX)
+	CV_FONT_ITALIC                 = int(C.CV_FONT_ITALIC)
+)
+
+type Font struct {
+	font C.CvFont
+}
+
+//void cvInitFont(CvFont* font, int font_face, double hscale, double vscale, double shear=0, int thickness=1, int line_type=8 )
+func InitFont(fontFace int, hscale, vscale, shear float32, thickness, lineType int) *Font {
+	font := new(Font)
+	C.cvInitFont(
+		&font.font,
+		C.int(fontFace),
+		C.double(hscale),
+		C.double(vscale),
+		C.double(shear),
+		C.int(thickness),
+		C.int(lineType),
+	)
+	return font
+}
+
+// void cvPutText(CvArr* img, const char* text, CvPoint org, const CvFont* font, CvScalar color)
+func (this *Font) PutText(image *IplImage, text string, pt1 Point, color Scalar) {
+	C.cvPutText(
+		unsafe.Pointer(image),
+		C.CString(text),
+		C.cvPoint(C.int(pt1.X), C.int(pt1.Y)),
+		&this.font,
+		(C.CvScalar)(color),
+	)
+}
+
 //CVAPI(void)  cvLine( CvArr* img, CvPoint pt1, CvPoint pt2,
 //                     CvScalar color, int thickness CV_DEFAULT(1),
 //                     int line_type CV_DEFAULT(8), int shift CV_DEFAULT(0) );

opencv/cxcore_test.go

@@ -1,9 +1,75 @@
 package opencv
 
 import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path"
+	"runtime"
+	"syscall"
 	"testing"
 )
 
 func TestLoadImage2(t *testing.T) {
 	// t.Errorf("aaa")
 }
+
+func TestInitFont(t *testing.T) {
+	// Will assert at the C layer on error
+	InitFont(CV_FONT_HERSHEY_DUPLEX, 1, 1, 0, 1, 8)
+}
+
+func TestPutText(t *testing.T) {
+	_, currentfile, _, _ := runtime.Caller(0)
+	filename := path.Join(path.Dir(currentfile), "../images/lena.jpg")
+
+	image := LoadImage(filename)
+	if image == nil {
+		t.Fatal("LoadImage fail")
+	}
+	defer image.Release()
+
+	// Write 'Hello' on the image
+	font := InitFont(CV_FONT_HERSHEY_DUPLEX, 1, 1, 0, 1, 8)
+	color := NewScalar(255, 255, 255, 0)
+
+	pos := Point{image.Width() / 2, image.Height() / 2}
+	font.PutText(image, "Hello", pos, color)
+
+	filename = path.Join(path.Dir(currentfile), "../images/lena_with_text.jpg")
+
+	// Uncomment this code to create the test image "../images/lena_with_text.jpg"
+	// It is part of the repo, and what this test compares against
+	//
+	// SaveImage(filename, image, 0)
+	// println("Saved file", filename)
+
+	tempfilename := path.Join(os.TempDir(), "lena_with_text.jpg")
+	defer syscall.Unlink(tempfilename)
+
+	SaveImage(tempfilename, image, 0)
+
+	// Compare actual image with expected image
+	same, err := BinaryCompare(filename, tempfilename)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !same {
+		t.Error("Actual file differs from expected file with text")
+	}
+}
+
+// Compare two files, return true if exactly the same
+func BinaryCompare(file1, file2 string) (bool, error) {
+	f1, err := ioutil.ReadFile(file1)
+	if err != nil {
+		return false, err
+	}
+
+	f2, err := ioutil.ReadFile(file2)
+	if err != nil {
+		return false, err
+	}
+
+	return bytes.Equal(f1, f2), nil
+}